No. 6. DEPARTMENT OF AGRICULTURE. 501 



wage a war against the fly and enter into the "Swat the Fly" cam- 

 paign, it will be necessary to go further than killing all the adult 

 flies and to prevent their coming into existence. 



The Health Officer of every community should see to it that every 

 section ef the town or city is kept scrupulously clean, if the sickness 

 in that town or city is to he reduce<l to a minimum. Many methods 

 have been suggested for taking care of the refuse material, such as 

 building closed receptacles in which to place refuse of all sorts, 

 removing it from time to time in closed wagons, and by the use of 

 chloride of lime, solution of Paris green, kerosene and other similar 

 substances. 



Bulletins have been issued by the United States Department of 

 Agriculture, in which instruction is given along these lines, and these 

 bulletins can be obtained by writing to the Superintendent of Public 

 Documents at Washington. 



The amount of money which has been spent for screens, fly paper 

 and fly poisons in the United States would amount to many thousands 

 of dollars, and the number of deaths, which cannot be estimated 

 in dollars, which can be directly traced to the fly, will reach into the 

 thousands. The value of real estate in fly infested districts has been 

 materially reduced, and wherever this pest thrives in great numbers, 

 it is easy to understand what an enemy they are. It is earnestly hoped 

 that a strenuous campaign will be waged in every community against 

 the unsanitary conditions which promote the breeding of flies, and 

 that no efl'ort will be spared to get rid of this pest and protect the 

 lives of our people. 



COMPUTING DAIRY RATIONS 



By PROF. H. E. VAN NORMAN, State College, Pa. 



In taking up the computing of rations, I shall outline my sugges- 

 tions in new terms — that is new to many of you who have for so 

 many years been discussing the feed problem in terms of protein, car- 

 bo-hydrates and fats. 



You known Dr. Armsby has been conducting his experiments on 

 the carbroymeter by means of which he measures the power of the 

 food content. For instance, if we have one hundred pounds of coal 

 in our fire machinery, it will turn into steam and this steam is the 

 energy that is required to do work. Our new term is simply measur- 

 ing the power of the food content by the power to do work. We 

 measure it by the amount of heat it would produce if burned up, but 

 all of the feed is not available for milk production; a part of it is 

 lost. There is a loss of ejiergy in the faeces, in the urine, in the 

 gases, in the labor of chewing, swallowing and digesting the food, 

 what is left is available for milk production and for energy stored 

 for a gain in weight. Therefore I am going to outline to you a 

 method of figuring it in terms of net energy, with the losses all taken 

 out. In the old metiiod only one loss was taken out. 



